Process for concentration of nonsulfide metallic minerals by froth flotation



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United States Patent Ofice 2,7245% Patented Nov. 22, 1955 PROCFAQS FOR CONCENTRATION OF NON- SULFIDE METALLIC MINERALS BY FROTH FLOTATION Stuart R. Zimmcrley and Martin W. Wilson, Salt Lake City, Utah, assignors to Kennecott Copper Corporation, a corporation of New York No Drawing. Application March 25, 1954, Serial No. 418,778

15 Claims. (Cl. 209166) This invention relates to the recovery of various metallic minerals of non-sulfide character from their ores by froth flotation, and is concerned especially with the application of particular reagents to the ore during the processing thereof for the purpose of modifying or activating the valued mineral particles, to render them amenable (or more amenable than they would otherwise be) to the action of collector reagents. v

Modification or activation is a Well-known phenomenon in the art of froth flotation, and usually involves surface alteration of the valued mineral particles to be recovered, as, for example, in the sulfidization of nonsulfide metallic mineral particles so that the common sulfide collectors will act to selectively float such particles relative to gangue constituents of the ore pulp. However, the activation may be due in whole or part to other factors which are too complex to be readily ascertained, but which are adequately evidenced by results obtained in practice.

In accordance with the present invention, one of a group of organic compounds heretofore proposed as a collector reagent in flotation practice applying to sulfide minerals is utilized as a modifier or activator in connection with various non-sulfide metallic minerals, usually by means of a conditioning stage carried out immediately in advance of aeration of the pulp.

The group of organic compounds concerned is the thioamides, represented by the formula R.CS.NH2. While, from numerous tests made, it is reasonable to suppose that all members of this group are useful to a greater or lesser extent, considering the particular ore to which applied, including those instances where R is either aliphatic or aromatic, we have obtained especially worthwhile results from that portion of the group where R is CnH2n+l, n being any whole integer from to 4, and from mixtures of members of such group. Of this more lim ited group of compounds, thioacetamide has proven of greatest all around usefulness.

The process of the invention has been applied with particular success to many ores containing non-sulfide minerals of heavy metals, which minerals have hereto fore been diflicult or even impossible to float by the use of known processes. For example, the mineral anglesite (a lead sulphate) has not heretofore been successfully floated by any known process, from ores or artificial mixtures containing same, yet excellent recoveries have been consistently made in tests applying the process of this invention. Likewise the mineral cerussite (a lead carbonate) and the minerals malachite and azurite (both copper carbonates) have been floated heretofore only with difficulty, yet very satisfactory recoveries have been easily made utilizing the present process.

One of the outstanding advantages of the invention is the fact that not only can better recoveries be made than heretofore in instances of these and other non-sulfide metallic ores, such as oxidized copper ores, but considerable savings can be eflected in the consumption of collector and frother reagents as compared with pulps not so treated and with conventionally sulfidized pulps.

A characteristic of the process is the persistence of the activation. Once applied, no stage additions of the reagent are required during the course of the flotation procedure.

Standard pH control techniques are substantially unafiected by the present process, and should be applied where indicated by the character of the particular ore being treated and of the particular reagents utilized.

The reagent of the invention may be applied to the ore in various conventional ways, for example, in the grinding circuit, in an advance conditioning stage, or during the flotation stage immediately prior to the application of the collector and frother reagents. Generally, however, it has been found most desirable to apply the reagent to the ore pulp, and to condition the mixture by agitation for a few minutes prior to the addition of the collector and frothing agents and prior to the commencement of aeration.

Conventional collectors and frothers are ordinarily employed, as indicated by the particular ore being treated. Thus, where treating oxidized copper ore from the Bingham Canyon properties of Utah Copper Division, Kennecott Copper Corporation, butyl xanthate has proven very satisfactory as the collector and pine oil as the frother. Again benzothiazole has operated successfully as the collector reagent in the recovery of the lead mineral from an artificial mixture of cerussite (lead carbonate), siderite, oxidized copper ore, and calcite,'pine oil being employed as the frother. In both of these instances thioacetamide was the activator reagent in accordance with the invention.

The beneficial and advantageous results obtainable by use of the new process in connection with normally diflicult or impossible to float, non-sulfide metallic ores, are indicated by the several typical examples set forth herebelow. Each example includes a set of comparative tests made, respectively, with and without activation in accordance with the invention.

Example No. 1

The ore utilized for this example was that mentioned above as being a naturally occurring oxidized copper obtained from the properties of Utah Copper Division, Kennecott Copper Corporation in Bingham Canyon, Utah.

The flotation procedure followed was normal in all respects, except for an initial conditioning of the pulp with thioacetamide, in test No. 1.

The tests of this example were made on respective 500 gram quantities of the ore, and were identical except that the ore was not activated in test No. 2. Butyl xanthate was used as the collector, on a quantitative basis of 0.9 lb. per ton of the ore, and both pine oil and Dow' froth were used as frothing agents, on the basis of 0.1 lb. per ton, respectively.

The thioacetamide was added to the prepared-ore pulp, in test No. 1, on the basis of 0.5 lb. per ton, prior to the addition of the collector and frother reagents, and the pulp was agitated for 5 minutes without aeration.- The other reagents were added in stages during the course of aeration of the so-conditioned pulp.

The following results were obtained:

Example N0. 2

For this example, the above-mentioned artificial mix ture of cerussite (lead carbonate), siderite, oxidized copper, and calcite was utilized, there being 60 gms., 5 gms., 430 gms., and 5 gms., respectively, of the component materials, making an over-all quantity of 500 gms., as in Example No. l.

The procedure corresponded to that followed in Example No. l, benzothiazole being employed as the collector reagent in both tests on a quantitative basis of 1.2 lbs. per ton. The frother reagent was pine oil, added to the pulp on the basis of 0.15 lb. per ton.

In test No. l, the pulp was agitated in the presence of thioacetamide, as an activator, the quantity utilized in this instance being on the basis of 1.2 lbs. per ton.

The following results were obtained:

Test N0. 1 Test No. 2 (Activated) (Not Activated) Cone. (grams) 74 16 Percent Oonc 14. 6 3. 2 Percent Pb 37. 5 19. 86 Percent Pb recover 73.2 10.8

Cone. (grams) 33 27 Percent Gone. 6. 5 5. 4 Percent Pb 22. 68 28. 61 Percent Pb recovery 19.7 26. 2

Cone. (grams) 12 16 Percent Gone. 2. 4 3. 2 Percent Pb 6. 2 23. 96 Percent Pb recovery. 2. 4 l3.

railings (grams) 387 438 Percent tailings. 76. 5 88. 2 Percent Pb 50 3.36 Percent Pb recovery 4. 7 50. 00

Total percent Pb recovery in concentrates".-. 95. 3 50. 00

The results obtained in the above examples of practical applications of our process are typical of what may be expected in the various procedures comprehended by the claims which here follow.

We claim:

1. In the process of concentrating non-sulfide minerals of heavy metals from ores containing same, the step of subjecting the ore in the form of a pulp to a flotation operation in the presence of an activating agent having the following general formula:

where R represents CnHzn-z-i and n is any whole integer from 0 to 4.

2. In the process of concentrating non-sulfide minerals of heavy metals from ores containing same, the step of subjecting the ore in the form of a pulp to a flotation operation in the presence of a thio alkyl amide as an activating agent, the alkyl radical of said agent having not more than four carbon atoms.

3. In the process of concentrating non-sulfide minerals from ores containing same, the step of subjecting the ore in the form of a pulp to a flotation operation in the presence of thioformamide as an activating agent.

4. In the process of concentrating non-sulfide minerals of heavy metals from ores containing same, the step of subjecting the ore in the form of a pulp to a flotation operation in the presence of thioacetamide as an activating agent.

5. In the process of concentrating non-sulfide minerals of heavy metals from ores containing same, the step of subjecting the ore in the form of a pulp to a flotation operation in the presence of a thioamide as an activating agent.

6. A process of concentrating non-sulfide minerals of heavy metals from ores containing same, comprising forming a flotation pulp of said ore; conditioning said pulp with a thioarnide; subjecting the so conditioned pulp to froth flotation in the presence of collector and frother reagents specific to the non-sulfide metallic mineral to be recovered; and recovering a froth concentrate of the said mineral to be recovered.

7. A process of concentrating non-sulfide minerals of heavy metals from ores containing same, comprising forming a flotation pulp of said ore; conditioning said pulp with a substance conforming to the following general formula:

R--NH:

where R represents CnHZn-H.

and n is any whole integer from 0 to 4; subjecting the so conditioned pulp to froth flotation in the presence of collector and frother reagents specific to the non-sulfide metallic mineral to be recovered; and recovering a froth concentrate of the said mineral to be recovered.

8. A process of concentrating non-sulfide minerals of heavy metals from ores containing same, comprising forming a flotation pulp of said ore; conditioning said pulp with a thio alkyl amide, the alkyl radical having not more than four carbon atoms; subjecting the so conditioned pulp to froth flotation in the presence of collector and frother reagents specific to the non-sulfide metallic mineral to be recovered; and recovering a froth concentrate of the said mineral to be recovered.

9. A process of concentrating non-sulfide minerals of heavy metals from ores containing same, comprising forming a flotation pulp of said ore; conditioning said pulp with a thioformamide; subjecting the so conditioned pulp to froth flotation in the presence of collector and frother reagents specific to the non-sulfide metallic mineral to be recovered; and recovering a froth concentrate of the said mineral to be recovered.

10. A process of concentrating non-sulfide minerals of heavy metals from ores containing same, comprising forming a flotation pulp of said ore; conditioning said pulp with a thioacetamide; and subjecting the so conditioned pulp to froth flotation in the presence of collector and frother reagents specific to the non-sulfide metallic mineral to be recovered.

11. A process of concentrating a non-sulfide mineral of a heavy metal selected from the group consisting ofnonsulfide minerals of copper and lead, comprising forming a flotation pulp of said ore; conditioning said pulp with a thioamide; subjecting the so conditioned pulp to froth flotation in the presence of collector and frother reagents specific to the non-sulfide metallic mineral to be recovered; and recovering a froth concentrate of the said. mineral to be recovered.

12. A process of concentrating a non-sulfide mineral of a heavy metal selected from the group consisting of nonsulfide minerals of copper and lead, comprising forming a flotation pulp of said ore; conditioning said pulp with a substance conforming to the following general formula:

i R-iJ-NH; where R represents cnH2n+l a thio alkyl amide, the alkyl radical having not more than four carbon atoms; subjecting the so conditioned pulp to froth flotation in the presence of collector and frother reagents specific to the non-sulfide metallic mineral to be recovered; and recovering a froth concentrate of the said mineral to be recovered.

14. A process of concentrating a non-sulfide mineral of a heavy metal selected from the group consisting of nonsulfide minerals of copper and lead, comprising forming a flotation pulp of said ore; conditioning said pulp with a thioformamide; subjecting the so conditioned pulp to froth flotation in the presence of collector and frother reagents specific to the non-sulfide metallic mineral to be recovered; and recovering a froth concentrate of the said mineral to be recovered.

15. A process of concentrating a non-sulfide mineral of a heavy metal selected from the group consisting of nonsulfide minerals of copper and lead, comprising forming a flotation pulp of said ore; conditioning said pulp with a thioacetamide; subjecting the so conditioned pulp to froth flotation in the presence of collector and frother reagents specific to the non-sulfide metallic mineral to be recovered; and recovering a froth concentrate of the said mineral to be recovered.

OTHER REFERENCES Taggart: Handbook of Mineral Dressing, 1945, section 12, pages 120 and 121. (Copy in Scientific Library.) 

1. IN THE PROCESS OF CONCENTRATING NON-SULFIDE MINERALS OF HEAVY METALS FROM ORES CONTAINING SAME, THE STEP OF SUBJECTING THE ORE IN THE FORM OF A PULP TO A FLOTATION OPERATION IN THE PRESENCE OF AN ACTIVATING AGENT HAVING THE FOLLOWING GENERAL FORMULA: 